


Enter Tony Stark, Steve Rogers, Barry Allen and a reluctant Leonard Snart

by Jessvampangel



Category: Captain America (Movies), Iron Man (Movies), The Avengers (Marvel Movies), The Flash (TV 2014)
Genre: Adorable Cisco Ramon, Awesome Natasha Romanov, Bisexual Barry Allen, Bisexual Steve Rogers, Bisexual Tony Stark, Crossover, Leonard Snart is a Softie, M/M, Natasha Romanov Is a Good Bro, Oblivious Steve Rogers, Pansexual Leonard Snart, Protective Barry Allen, Protective Tony Stark
Language: English
Status: In-Progress
Published: 2016-12-28
Updated: 2016-12-28
Packaged: 2018-09-12 23:57:37
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,986
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9096226
Author URL: https://archiveofourown.org/users/Jessvampangel/pseuds/Jessvampangel
Summary: "But then why are we here? Why us specifically?""I am sure that, if he watches you two for even a short amount of time, he will see how beautiful my world really is and decide it IS worth saving, and I am willing to be open to the idea that, through watching Mr Snart and Mr Allen, I may see the beauty in his. Right now, Mr Stark, your ability to entertain is the only thing keeping everything you know and love from being torn apart."***The creators of DC and Marvel don't get along. However, it takes a major rupture in the fabric of the universe for one of them to realise they need to settle their differences. Only problem is, they can't talk to each other for more than five seconds without insulting each other, accidentally or not. So somehow, they have to understand why each universe is important, in it's own way.Enter Tony Stark, Steve Rogers, Barry Allen and a reluctant Leonard Snart.





	

**Author's Note:**

> Okay, so I was so tired at the point of writing this that I didn't even KNOW how tired I was, so if you do like it, please tell me down in the comments XD I'll probably go back to fix the many, MANY errors at some point in the future.

It is well known that one Tony Stark does not get along with one Steve Rogers. You don't have to be a self titled genius, billionaire, playboy, philanthropist to know that. They only had to stand in a room together to rub each other the wrong way. They had both spent lengths of time attempting to get along - Tony more subtly, but attempts were made - but no matter who tried, they just couldn't seem to listen to each other. Most days, like when the Avengers had their movie nights and the tension couldn't go unnoticed in the room, Natasha would simply threaten castration should either of them even speak to each other, but other times it was unavoidable.

 

Post-battle lectures, for example.

 

"For god's sake, Stark! Can you not for once just trust in my judgement and follow my instructions? One of these days you're going to get yourself killed and it's going to be on my conscious!" Steve yelled. He couldn't tell you how many times they'd had this argument - he'd lost count at around ten. But he never stopped having it; he had long ago accepted his fate and resigned to repeating his words until they actually managed to penetrate the ego of the man currently stood in front of him.

"What would you rather I do?" Tony yelled back, because never let it be said he didn't give as good as he got. He, too, had long ago accepted his fate of receiving these talking to's after every single battle - because Captain America didn't trust him, and quite frankly, he didn't trust Captain America. "I'm expendable, Cap, everybody is! We're supposed to be fighting to save the world, and quite frankly, I'd rather get the job done than wait until you decide it's safe enough!"

 

"Nobody is expendable, Tony!" Steve was only getting angrier at this point, and it must have shown in his voice. "Not you, not any of the Avengers! Thor was going to do it, he was ready to do it, and he was in a safe position to do it! You didn't need to take it upon yourself, and god knows nobody is happy you did!"

 

Tony wanted to start screaming back, because how dare Steve assume he gave a shit about what anybody thought, how  _dare_ he, but his attention was suddenly captured by something considerably more pressing. The world was suddenly falling away, rapidly decreasing in size, all of the colour turning to a dull blue, everything becoming nothing but blueprints. It was decreasing so rapidly in fact that Tony only had chance to comprehend it before it was upon him, hitting his body as well as Steve's. He felt nothing.

 

* * *

 

When he saw again it wasn't a bright light like he for some reason he expected. He was in a world of very similar creation, even though he was coloured in. As he looked around, he took note of several things - although this place was the same, it was all flat, like a new canvas. There were various other bits of colour with him too - only one of which he recognised.

 

"Oh god, of all the people I could be stuck in this situation with," Tony groaned as he moved towards him. Steve looked up to him from his position of lying on the ground, eyes narrowing almost instantaneously (automatic reaction, Tony supposed). Tony extended his hand to him, considering somebody had to take initiative in this situation and put forward the idea that they should probably focus on their current predicament over their previous argument. Steve took his hand, allowing himself to be hoisted up, and then Tony's attention turned to the other two figures.

 

One of them was in a bright red suit. He was stood up, watching them curiously, eyes narrowed. Tony only looked him up and down once before turning to the other figure. He was still out cold, lying on the ground. He wore a blue parka, head outlined by a fur hood, although it had fallen away and was actually pooled around his head, rather than covering it.

 

The first figure moved over to Tony and Steve, eyes still narrowed quizzically. Once he reached them he looked Tony up and down, most likely taking in the suit. Realising he still had the visor up, Tony opened the head plates, showing the boy that, yes, he was human. This didn't seem to make him any less apprehensive, though. "Who are you?"

 

"Tony Stark, nee Iron Man. This is Steve Rogers, or Captain America." Tony answered with ease, shifting his head slightly towards Steve as he said his name. Steve nodded along, although he didn't look happy about it. The simple fact was, he wasn't adaptive. Tony liked to learn about situations and environments through interaction, whilst Steve liked to stand back and observe primarily. It was only one the major differences between them. "And you?"

 

"The Flash." The boy responded, and by now it was clear he was young from the pitch of his voice and his body shape. He looked to the other man, as if considering something, before carrying on. "That's Leonard Snart, or Captain Cold, as we call him. So, you guys are superhero's, from the looks of things." He turned to Steve then, looking his up and down quickly. "The robotic suits pretty self explanatory, but what's with you? Are you a metahuman?"

 

"Metahuman?" Steve repeated, brow furrowing. Tony was considering the word too. It was unusual, definitely something he'd never heard before. "Are you talking about mutants?"

 

"Mu- do you call them mutants? That's a little bit cruel, don't you think?"

 

Steve only looked more confused as he said that, but he didn't get to reply because another voice joined in the conversation, this one echoey and practically deafening. "Children, playtime is over. It's time to listen."

That captured everybody's attention. The sleeping figure finally arose, and his reaction was immediate - he practically jumped up from the ground, somehow graceless; in fact, he bared some resemblance to a cat in the way he moved. His eyes were flittering between each of them, judging, but the presence of 'The Flash' (Tony had to get the kid's name as soon as possible, there was no way in hell he was calling him that constantly) seemed to calm him. "I am sure you are all wondering why you are, and who you all are. You are actually pairs of individuals from different universes - the dc and marvel verses. I am the creator of one of these. Recently, there has been somewhat of a disturbance in these universes. You do not need to understand the nature of this, only that it was caused by a... difference in opinion by myself and the creator of the other universe."

 

"Sounds like the kind of thing we've dealt with before." Tony shrugged it off with nonchalance, knowing full well that these matters occurred. It was out of his or anybody else control - in reality, they were the playthings of higher beings, he had learnt that lesson long ago. It didn't mean he was going to bow to them, or talk to them as if they deserved such. If the least he could do was pretend to them that he was superior, then damn he was going to do it. "But then why are we here? Why us specifically?"

 

"I am sure that, if he watches you two for even a short amount of time, he will see how beautiful my world really is and decide it IS worth saving, and I am willing to be open to the idea that, through watching Mr Snart and Mr Allen, I may see the beauty in his. Right now, Mr Stark, your ability to entertain is the only thing keeping everything you know and love from being torn apart." The voice responded, and that brought about a little bit more of a pressing desperation than her previous sentence had. "Am I understood, Stark? I know how you turn a blind ear to those things you don't want to hear."

 

Tony scoffed, ignore the little giggle that came from Steve. There was a hint of humour in her voice, and he certainly did not find it amusing. "I listen, I just don't respond. There's a difference."

 

"I appreciate that. I will consider it in the future." She finished in such a way that made Tony think she was never going to consider it again, and he would be lying if he said that wasn't ever so slightly irritating. But it didn't seem like his place anymore to respond (he rarely cared, but he knew when he was under someone else's shoe, and contrary to popular belief he knew just when was too much) so he didn't say anything further. "You will be able to see each other, since you will only be weakly tied to each other's universes. You will be there, but you will also partially be here, so you will see each other at all times. If it is necessary, do guide each other. Given the lives you seem to each lead, I imagine it will be necessary. But until this issue is resolved, you won't be returning to your host universe's. I would ask you if that's okay but, well, you don't actually have a choice."

 

* * *

 

 

 _This_ time, when Tony opened his eyes (and, really, who treats guests like that, it's just plain rude) he was in the middle of a lab he didn't even mildly recognise, and there was yelling going on around him. Rather loud and worried yelling, actually. Annoying yelling. He laid a hand on his forehead, allowing the coolness to calm him, before sitting up on what appeared to be an operating table. He looked around himself and was met with the face of a young man, who had extremely wide eyes. There was another woman behind him, significantly more put together but still a little bit frantic. "Cisco, you're not helping! Stand back, he could be dangerous!"

Tony tried to tune out of their yelling and suddenly found himself in a different place, a wispy image of where he had been before, next to the two figures from the blueprint based room. His head was swimming and he now found himself wishing back, and as he did so he was. Now back in the lab, with the woman still yelling and the man moving away from the operating table, he placed his head in his hands, taking a deep breath, doing his best to not flip out and shoot one of them with a repulser blast. It probably wouldn't result in a friend. Finally, they seemed to calm down, and the woman focused on him. "We want to know who you are, right now. Where you came from, and what you did with Barry."

"Barry?" Tony asked, wondering briefly whether he'd accidentally caused the death of/resulted in the kidnapping of somebody else, before he remembered what situation he was in and who Barry probably was. "Oh, is he the kid in the red spandex?"

"It's not- why does everybody think we let him go out in spandex?" The boy, now apparently irritated, murmured from the other side of the room. The girl shot him a look and he was instantly silenced. That only amused Tony. "I'm shushing now. Not going to talk again. Pinky promise."

"Barry was in his suit last time we saw him, yes." The girl explained, completely ignoring his rambling. Tony listened to her, quickly putting the pieces together. This must be the other universe, the one the woman had spoken of. And that meant it was the flash and Leonard Snart's universe. Whoever they were. Considering the situation he was in, The Flash was obviously this worlds superhero. Looking around, it was a huge step down from Avengers tower. "He was also sat where you currently are last time we saw him. Approximately a minute ago, actually. He had just come back from a mission and we were getting ready to stitch him up, when suddenly he disappears, and you're left in his place. So, I'll ask again - who are you, and where you did you come from? What did you do with Barry?"

"Name's Tony Stark, apparently from a different universe." Tony held him hand out and, upon her not shaking it, promptly returned it to his side. She was strong, he could respect that. Reminded him of Pepper. And, to a lesser extent, Clint (ha, you thought he was going to say Natasha. Natasha isn't just strong, she's terrifying). "Tough crowd. Listen, I don't know much more than you do. I was minding my own business, in my  _own_ universe, when I got pulled into some kind of neutral domain. A woman spoke to myself and my teammate, as well as your Barry and somebody he named as Leonard Snart."

Instantly, she flinched. Tony raised an eyebrow at that. "Not a good guy then, huh?"

"You could say that." The boy spoke up again, and this time he went unstopped. He looked equally as grim, fists clenched slightly. "He's a villain, goes by the name 'Captain Cold'. Barry's nemesis to be precise." He explained, and suddenly everything seemed to make a lot more sense. After all, every good superhero has a nemesis.

"Okay. Well, that woman said that the two universes were clashing, and that the only way to prevent them from being torn apart was to prove how beautiful each world is to the other world's creator. So, she's sent the two most interesting people from each to the opposite world." The boy raised his eyebrows as he said that, and Tony only rolled his eyes. "Her words, not mine."

"Okay, Tony Stark." The girl took a step back, seemingly accepting his explanation. The boy seemed a little bit surprised that she had, but Tony was just glad he didn't have their constant pressure lumped on him like a rock. He felt significantly more relaxed now. "You said there were two of you, and that both got swapped to the opposite world. Where's the second?"

"What, Cap's not here?" Tony felt a hint of worry flash through him at that, not that he'd ever admit it out loud. A quick glance around the room proved his answer in the positive, and he felt his whole body go rigid. He and Steve didn't get along, but he certainly didn't want him stuck in another universe and not necessarily safe. "Well, I suppose we've got to find him them. If I'm in Barry's place, then he must be in Leonard Snart's."

They were both instantly on the defensive again now. Rigid and firm. Tony recognised that reaction anywhere. It was hardwired into people who went into the business of saving the world. The somethings-obviously-wrong-here-and-I'm-not-certain-what-to-do-about-it reaction. "If he's where Leonard Snart used to be, then he's either on a travelling time ship with a crew of legends, on a heist or in a hideout somewhere in Central with a bunch of hero-hungry super villains," the boy concluded his suspicion, and Tony only let out a groan at that, moving off the operating table.

"Let's hope it's the latter. The idiot wouldn't beat the police up if they caught him and I don't like travelling through time. Messy business." He concluded, moving towards the door. They both looked startled, frozen in place, but quickly caught up, with the boy running after him frantically. "Uh, but we don't really want him surrounded by super villains either, really. That wouldn't be good. But, um, I don't really know how you plan to find him. Wherever he is, he's not going to be on camera's or anything like that."

"I fitted him out with a tracker a long time ago. Don't trust him as far as I can throw him, and that dude looks heavy." Tony kept walking, tapping on a screen as he did so. The boy followed beside him, struggling to keep up with his pace. "And regarding the super villain thing, he'll be fine. Cap survived World War Two, you know." The look he sent him when he said that reminded Tony that he  _was_ in an alternate universe, and he couldn't expect everything to be the same, even if it same pretty similar at the current moment in time. "Did you guy's have World War Two here?"

"We did," The boy confirmed, and that was a relief. Clearly there were going to be plenty of parallels between the two universes. In fact, so far, there didn't seem to be many differences at all, other than the people in them. "Just, a long time ago. The few people who are still around fought in it a long time ago. They're certainly not still fit to be fighting. And, um, it's not really the same thing."

"Oh, ours was a long time ago too," Tony confirmed, smiling at the boys naivety. It was cute, really. But then, there were definitely things he had yet to learn. He was open minded - it wasn't really his place to judge. "He's just got tough skin, our Cap. You'll understand when you meet him." The screen gave out a sudden loud, obnoxious beep, and that only caused Tony to groan again. "Of course. A tracker wouldn't work here, would it."

The boy instantly reached over and grabbed the tablet from his hands, eyes widening in glee at the very sight of it.  _Oh, please tell me they have technology here,_ Tony found himself thinking. Because, with the same furniture as his universe being everywhere, it would be his luck that the one thing, the  _one thing_ they didn't have the same would be the existence of technology. "Oh, I think I can reconfigure this. Yeah, should be easy enough. It will take some time though."  _Oh, thank god._ Tony allowed himself to breath again. As if suddenly recharged, the boy held his hand, much like Tony had earlier, with a bright smile. "I'm Cisco Ramon. She's Caitlin Snow. Welcome to our universe, Tony."

Tony took his hand and shook it, returning the smile. The kid seemed intelligent enough, and he could get along with anybody smart enough to keep up with him. Besides, he needed to stay on his good side - he did need the tracker updating after all, and although he could do it himself, it would be much easier for somebody who knew about this universe to do it. The girl, Caitlin, was now behind them again, and she paused their introduction quickly. "I should probably let Joe and Iris know about this, before they start worrying about Barry."

She then rushed off ahead, and Cisco started to follow, still tinkering with his new toy. It was certainly refreshing for Tony to find somebody who knew his way around a piece of tech he had designed. He had wit, too, that much was clear. "Come on then, Tony. We don't have all the time in the world. See, it's funny, cause we actually don't." Cisco glanced at him as they moved, furrowing his brow, and then continued. "What's with the suit, by the way? Not that it doesn't look awesome, cause it does. Look awesome, I mean. Remind's me of Palmer's."

Tony decided to ignore the inference that somebody had a suit as powerful as his (because the mere thought of it was hilarious) and instantly took it upon himself to launch into an explanation. "In my universe, I'm known as Iron Man. This suit is my battle gear. Made it myself. I'm part of a superhero group called the Avengers, base of operations New York city. My dear Cap, as in, Captain America, is also a part of that group. Arguably the leader."

Cisco looked absolutely enthralled, just as Tony had expected him to react. It was rare he met somebody who didn't know who he was. For the moment, he would relish in it. "But I thought you said he fought in World War Two? If that was anywhere near as long ago as it was on  _our_ universe in yours, then he should be way too old to be fighting in a group of superheroes."

"Ah, that's a long story." Tony grinned, and just as soon as he said it, he decided it was definitely worth telling.

 

* * *

 

 

Tony was in the middle of the story when he was interrupted by the ghost form of Barry. It startled him, sure, but not enough for a visible reaction. Barry looked terrified. "Tony! Ah, Mr Stark! I have a bit of a dilemma back on your universe!" He then stopped for a second, looking around and narrowing his eyes. "I, uh, see you've gotten comfortable in mine."

"Tony?" Cisco asked, looking up from where he had been working on the tracker. They were currently in the cortex, as Cisco had told him, and Caitlin had disappeared on a phone call. "What's up? You suddenly stopped talking."

"You can't see him, huh?" Tony asked, and, after glancing around, Cisco shook his head. He was far more alert now, though. "Barry's here. In ghost form, though. I'm assuming this is what that woman meant when she said we could see each other. What can I do for you, Barry?"

"There's a woman here," Barry began immediately, momentary confusion suddenly forgotten in his hurry. "She found Snart and I really quickly. She, uh, won't believe me when I say I'm from a different universe. Won't stop saying that I've kidnapped you. We're in some kind of tower? Anyway, I could really do with you coming to me, instead of me to you, so you can guide me on this?" He stopped and, as Tony's expression, smiled sweetly. "Please?"

"Alright, give me a second." Tony agreed, and the look on Barry's face could only be described as relief. Then he was gone, just as quickly as he had appeared. Cisco stared at him now, waiting for an explanation. "He needs help. I think I can cross into my universe, but I can't be seen by anyone except him and Snart. I'll probably still be here, so... do you mind me, slipping out a bit? I'll still be here technically."

Cisco looked slightly weirded out but he nodded, and then Tony focused on existing in his own universe, with Barry. He slipped into it quickly, like he had when he'd accidentally done it before, and then he was in the common room of Avengers tower. Sat with him was Barry and a disinterested Leonard Snart, sat on a chair about as far away from Barry as he could get. He had a super villain aura to him now he was awake, that wasn't debatable. In the room with them was Natasha and Clint, both looking menacing (although Natasha significantly more so). He had to be fair however - Clint polishing his bow would probably seem scary to somebody who didn't know he'd stolen the last cookie the night before (and damn him because that was Tony's, he fucking  _bagsied!)_

"Oh, thank god, Tony." Barry sighed out. He no longer had his cowl up, Tony noticed, probably on Natasha's command, since he'd been hesitant to reveal his identity when Tony had first met him. "Please help me out here. Miss Romanov wants to hear me say something only you'd tell me to say."

God, the kid really screamed Peter Parker, didn't he?

"Tell her I know she thinks I'm hot, she just won't admit it because she's stubborn." Tony told him nonchalantly. Barry practically choked when he first heard it, and he looked reluctant to say it, but he repeated it with fairly little resistance. Natasha rolled her eyes after she heard it, but she smiled too.

"Alright, yeah, that's Tony." Clint agreed, putting his bow down. Now relieved of stand-and-look-scary mode, he moved over to the mini fridge and grabbed a beer, popping it out with a hiss. Barry watched him, hesitant, but he was obviously put at ease by the words.

Tony left them to it after that. Besides, it was up to Barry and Leonard to deal with his weirdly shaped family for now, he had to deal with theirs. And find Steve. That should probably be called a priority too.

When he returned Cisco was in the same place as before, although he kept side eyeing him every now and again. After a moment of this he finally spoke. "You back, huh? Gotta tell you, that's really freaky man. You just sat there and... talked."

"Guess it's a package deal." Tony shrugged, pointed out a flaw in Cisco's design work, and just like that they were back into the pace of things.

 

* * *

 

 

Steve was in a hideout somewhere in Central with a bunch of hero-hungry super villains, thank god. As soon as Cisco was able to tell him that Tony asked to be shown out of the labs (Star Labs, as Cisco had told him it was called). Once they were outside Tony could tell Cisco had something to say, so he asked him about it, just to be polite before he left. "What's up, Cisco? Something's obviously bothering you, and I don't need that bothering  _me_ while I'm doing this."

"Can I come with?" Cisco suddenly blurted out, and to be honest, that wasn't what Tony expected. Cisco was obviously a great kid, he'd learnt that in the half an hour or so he'd spent with him. Caitlin seemed pretty decent too, from what he'd seen of her, although she hadn't really paid him all that much attention. But they both seemed like behind the scenes kinds of people - Barry was obviously the one who put himself in the line of fire. So he didn't really understand what Cisco could gain. "I do have powers. I'm a metahuman, as they call us here. It's hard to explain, but I can fight. And I'd like to come with. So I could show you the way back afterwards."

It made sense, Tony knew that. And if Cisco thought he could fend for himself then he may as well allow it. It wasn't his job to tell anybody what to do, this wasn't his team. If Cisco stayed out of his way then there was no reason for it to be a problem. "Alright then, kid. Don't scream."

Cisco was about to ask what for but Tony didn't let him, wrapping an arm around his waist and setting his boots off.

Cisco did scream. Loudly. And for practically the entire journey.

In fact, by the time they reached the hangout, Tony was afraid he wasn't going to stop.

He set down onto the ground and let Cisco go, who scrambled away as quickly as possible. Tony flipped his visor up once again, certain the amusement must be showing on his face, and watched as Cisco's eyes widened and he tried to regain his balance. "That was... I don't... that was... weird. And new. Felt a lot like running with Barry. Except... higher. I don't like heights. But I've got to admit, that was pretty cool."

"Glad you think so," Tony grinned, before approaching the building where the tracker said Steve was. Although the neighbourhood was seedy and there wasn't anybody about, he didn't want to wait until somebody turned up. Explaining the suit to a ton of people who had no idea what or who he was would be a pain. He kicked the door open (no quarrel there) and heard yelling from the floor above. He quickly ran up the stairs, putting the vizor back on just in case, taking note of Cisco running after him, but by the time he reached the top of the stairs it was all over. Steve was stood at the top, shield in hand, surrounded by what must have been ten or more people, as well as burnt sections of wall, glittering sections (that couldn't be gold. Why would there be gold?) and various other weird and wonderful after-fight decorations. Steve, for the first time ever, looked relieved to see him.

"Tony!" He grinned, moving over. His chest was moving rapidly, and he was clearly tired, but he wasn't cut anywhere, so Tony wasn't too worried. Steve seemed to take note of Cisco behind him and stopped his advance, frowning. "Hi?"

"O Captain, my Captain!" Tony smirked, folding his arms as he faced Steve. It was a power play, and both men knew it equally well. Tony had the upper hand here, he knew far more about the situation, and hell was he going to rub it into Steve's face. "Meet Cisco Ramon! He has assisted me greatly in finding you here. A friend of Barry's, aka the boy in spandex we met earlier."

"It's not spandex!" Cisco practically spat, but he seemed a little awestruck. After all, Tony had spent a considerable amount of the time they'd known each other telling him all about Captain America. A mistake, Tony realised, in hindsight. "Uh, Mr Rogers, great to meet you. Heard a lot about you. Well, not that much, Tony was selective. Well, a bit selective. I don't  _about_ you, to be honest. What kind of person you are really. But, uh, you seem like a cool person."

Steve, damn smooth devil that he was, and much to Tony's disdain, smiled back and moved over to Cisco, grabbing his hand and shaking it (vigorously, although Tony was sure Cisco would never mention it). "Good to meet you too, Cisco. Tony would do that. Thank you for your help."

It was with that, that he turned to Tony, grim features returning.  _Story of my life._ "Not that it isn't great that you're making friends, Tony, but I'm a little worried about our current situation. What have I missed?"

Tony smirked again at that. "Oh honey, _a lot_."

**Author's Note:**

> Can I just say, Cisco and Tony would get along so well, and nobody can tell me otherwise. I get the feeling Natasha and Len would clash a little though. Eh, we'll see, I suppose.


End file.
